Phenolic constituents from Ammania auriculata Wild: Structures, antioxidative activity and cytotoxicity
Chemical investigation of Ammania auriculata WILLD. whole plant extract resulted in the identification of 23 polyphenolic compound for the first time from this plant, including two hitherto unknown flavonoids; kaempferol 3-O-β-(6”-galloylglucopyranoside)-7-O-β-glucopyranoside (13) and its quercetin (14) analogue . The structures of all isolated compounds(1 – 23) were elucidated by conventional methods, spectroscopic analysis, including one dimension and two dimension NMR as well as by high resolution electrospray ionization mass spectromety. The whole plant extract and some of the isolated compounds were investigated for their antioxidant activities, determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Oxygen radical absorbance capacity (ORAC-assay), and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis . Compounds 1, 3, 4, 7, 9 and 14 significantly inhibited reactive oxygen species production with An half maximal effective dose (ED50) values between 3.22 and 9.79 µg/ml. Compounds 1, 9 and 20 showed cytotoxic activity against HaCaT cells, with half maximal inhibitory concentration (IC50) values of 84.1; 82.1 and 184.2 µg/ml, respectively.
Keywords: Ammania auriculate, polyphenols, kaempferol 3-O- β-(6”-galloylglucopyranoside)-7-O-β-glucopyranoside, quercetin 3-O- β-(6”-galloylglucopyranoside)-7-O-β-glucopyranoside
 Markham, K.R., Ternai, B., Stanley, R., Geiger, H., Mabry, T.J. 13C NMR studies of flavonoids – III. Naturally occurring flavonoid glycosides and their acylated derivatives. Tetrahedron 1978; 34: 1389.
 Nordberg J, Arner J. Reactive oxygen species, antioxidants, and the mammalian thioredoxin system. Free Rad Biol Med 2001; 31: 1287 – 1312
 Nawwar M, Swilam N, Hashim A, Al-Abd A, Abdel-Naim A, Lindequist U. Cytotoxic isoferulic acidamide from Myricaria germanica (Tamaricaceae). Plant Sign Behav 2013; 8: 33 – 41